package com.example.testgallery;

import android.R.attr;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Camera;
import android.graphics.Matrix;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.Transformation;
import android.widget.Gallery;

public class MyGallery extends Gallery {
	
	  private Camera mCamera;
      private int mWidth;
      private int mPaddingLeft;
      private boolean flag;
      private static int firstChildWidth;
      private static int firstChildPaddingLeft;

     
      public MyGallery(Context context) {
              super(context);
              mCamera = new Camera();
              this.setStaticTransformationsEnabled(true);
      }

     
      public MyGallery(Context context, AttributeSet attrs) {
              super(context, attrs);
              mCamera = new Camera();
              //setAttributesValue(context, attrs);
              this.setStaticTransformationsEnabled(true);
      }

     
      public MyGallery(Context context, AttributeSet attrs, int defStyle) {
              super(context, attrs, defStyle);
              mCamera = new Camera();
              //setAttributesValue(context, attrs);
              this.setStaticTransformationsEnabled(true);
      }

      private void setAttributesValue(Context context, AttributeSet attrs) {
              TypedArray typedArray = context.obtainStyledAttributes(attrs, new int[] { attr.paddingLeft });
              mPaddingLeft = typedArray.getDimensionPixelSize(0, 0);
              typedArray.recycle();
      }

      protected boolean getChildStaticTransformation(View child, Transformation t) {
              t.clear();
              t.setTransformationType(Transformation.TYPE_MATRIX);
              mCamera.save();
              final Matrix imageMatrix = t.getMatrix();
              final int imageHeight = child.getLayoutParams().height;
              final int imageWidth = child.getLayoutParams().width;
              if (flag) {
                      firstChildWidth = getChildAt(0).getWidth();
                      firstChildPaddingLeft = getChildAt(0).getPaddingLeft();
                      flag = false;
              }
              mCamera.translate(firstChildWidth / 2 + firstChildPaddingLeft + mPaddingLeft - mWidth / 2, 0f, 0f);
              mCamera.getMatrix(imageMatrix);
              mCamera.restore();
              return true;
      }

      protected void onSizeChanged(int w, int h, int oldw, int oldh) {
              if (!flag) {
                      mWidth = w ;
                      getLayoutParams().width = mWidth;
                      flag = true;
              }
              super.onSizeChanged(w, h, oldw, oldh);
      }

      @Override
      public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
              // TODO Auto-generated method stub
              // return super.onFling(e1, e2, velocityX, velocityY);
              return false;
      }

      @Override
      public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
              // TODO Auto-generated method stub
              return super.onScroll(e1, e2, distanceX, distanceY);
      }

}
